Voice over IP (VoIP) has become an important factor in network communications, promising lower operational costs, greater flexibility and a variety of enhanced applications. To help you understand VoIP networks, Voice over IP Fundamentals explains how a basic IP telephony infrastructure is built and works today, major concepts concerning voice and data networking and transmission of voice over data networks. You'll learn how voice is signaled through legacy telephone networks, how IP signaling protocols are used to interoperate with current telephony systems and how to ensure good voice quality using quality of service (QoS).
Even though Voice over IP Fundamentals is written for anyone seeking to understand how to use IP to transport voice, its target audience comprises both voice and data networking professionals. In the past, professionals working in voice and data networking did not have to understand each other's roles. However, in this world of time-division multiplexing (TDM) and IP convergence, it is important to understand how these technologies work together. Voice over IP Fundamentals explains all the details so that voice experts can understand data networking and data experts can understand voice networking.
The second edition of this best-selling book includes new chapters on the importance of billing and mediation in a VoIP network, security and the common types of threats inherent when packet voice environments, public switched telephone networks (PSTN) and VoIP interoperate. It also explains enterprise and service-provider applications and services.
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In this chapter:
Billing and mediation services are important in Voice over IP (VoIP). They are key factors in helping a service provider or an enterprise vendor understand financial aspects -- such as Return on Investment (ROI) -- when migrating from time-division multiplexing (TDM)-based network to VoIP. The public switched telephone network (PSTN) world offers a simpler billing structure for calls made over the network because the originator and the destination points are static and tied to a physical location. It also expects voice traffic and data traffic to be billed in different ways. VoIP changes this paradigm and allows the endpoints to move. The voice and data traffic are all packets that are transported from one location to another over the network. This raises some issues and requires protocol definitions on whom to bill, where to bill and what to bill. Chapter nine of Voice over IP Fundamentals discusses what network administrators need to know about combining voice and data while maintaining organization and concise records.
Read more about VoIP billing and mediation services in this PDF.
Excerpted from Voice over IP Fundamentals, Second Edition, July 2006 by Jonathan Davidson, James Peters, Manoj Bhatia, Satish Kalidindi, Sudipto Mukherjee. ISBN: 1-587-0525-71.
Copyright © 2006, Cisco Press. All rights reserved.
